Spring controlled guide rod for the oil port valve of an accumulator



ZJV'VEJV T0]? 5 EDWARD M. EH55]? JEA/V 5505555 MERZ'JSR' J. G. MERCIERETAL SPRING CONTROLLED GUIDE ROD FOR THE OIL PORT VALVE OF ANACCUMULATOR Filed Sept. 30, 1948 Match 27, 1951 ATTORNEY Patented Mar.27, 1951 UNITED STATES QFFHCE.

SPRING.- GGNTRGLLED GUIDE ROD F03 THE OIL PORT VALVE 0F AN ACCUMULATORJean Georges Mercier, New York, and Edward M. Greer, W est Hempstead, N.2.; said Edward M. Greer assignor to Greer Hydraulics, Ina,

Brooklyn, N. Y.

Application September 30, 1948, Serial No. 52,054

4 Claims.

port from closing same when the accumulator is completely exhausted.

In a hydraulic accumulator in which compressed air or gas is normallystored within the bladder or bag mounted inside the accumulator shell asan energy storage means, a fluid is forced into the fluid port of saidaccumulator shell at a pressure greater than the pre-loaded gas pressurecharged within the bladder. In utilizing this device the accumulator isnormally connected to a hydraulic system or device and with fluidcharged under pressure within the accumulator, the system or device maybe supplied by this stored pressure fluid as it is discharged from theaccumulator whenever the fluid pressure in the system or device dropsbelow the pressure of the fluid stored within the accumulator, thisdischarge being accomplished by the energy storage device (bladder).With a deformable bag or bladder, there is a tendency for the bag toforce itself or cause the extrusion of the rubber of the bag through thefluid exhaust port after the fluid has been discharged from theaccumulator. Various modifications have been attempted to prevent to thbag such as the pending applications of Edward M. Greer, Serial No. 664893 filed April 25, 1946 and Serial No. 755,592 filed June 19, 1947 andas also illustrated in Patent No. 2,342,356 issued February 22, 1944 toJean Mercier. However this undesirable tendency produces a stress on theportion of the bag nearest to the oil discharge port and it has beenfound that many of the bags in use do rupture at this particular pointor area. tion there is provided a protective button afflxed to theportion of the bag nearest to the fluid exhaust port and although thisaccomplishes one means of preventing the extrusion of the bag or bladderthrough the discharge port, the undesirable stresses in this particulararea of the bag stiil exist. In the other cpl-pending application, thereis provided in addition to the protective button aflixed to the portionofthe bag nearest to the fluid exhaust port a valve stem or guide rodwith a resilient spring mounted between the exhaust port and theprotective button or valve head, to thus resist the closing of the valveor button, to resist the normal tendency of the bag to be extruded orforced into In the one co-pending applica- I the exhaust port. Althoughthis improvement does assist the bag or bladder in its final closing .ofthe fluid port, there is a great deal of stress produced about theperiphery of the bag at the area adjacent to the fluid oil dischargeport. The issued patent before mentioned illustrates a similar device inwhich the valve stem is not guided and the normal operation of the bagor bladder is quite similar to the pending applications mentioned.Unfortunately in a number of installations, the bag or bladder which ispro-designed with equally stressed Walls does not perform in thepre-determined manner of expanding and contracting in a perfectconcentric formation, but rather assumes a 1opsided or twisted formationand in such defective formation, in the one instance with the protectivebutton does not seat the button on the fluid exhaust port and the bagmay be ruptured in such instance. Likewise in an installation similar tothe patent mentioned when the bag or bladder is deformed, the valve rodbetween the lower portion of the bag and the valve seat will be twistedand thus prevent the valve from seating in a concentric manner and thusproduce an unnatural stress in the bag which may cause a rupture in use.Similarly in the pending application in which the valve rod is guidedwithin the discharge port when there is any fluid trapped such as whenthe accumulator is used in a horizontal position there may be alop-sided or twisted formation of the bag or bladder, in such instancean unnatural stress is produced about the area of the bag adjacent thevalve head and fluid discharge port.

It is an object of this invention to provide an accumulator having adeformable bag or bladder therein, with a fluid discharge port in oneend thereof and a gas charging port at the other end thereof, in which aresilient restraining means is attached within the bag at the zone ofthe bag or bladder adjacent the fluid discharge end of the accumulator,and said resilient restraining means is provided to prevent the stressesin the bag or bladder about the area of the bag or bladder adjacent tothe fluid discharge port.

A still further object of this invention is to provide a means mountedwithin a deformable bag or bladder in combination with the fluiddischarge port of an accumulator to restrain the portion of the bagadjacent the fluid port from expanding to close said fluid port duringthe normal discharge of fluid from said accumulator.

A still further object of this invention is to provide a means mountedwithin a deformable bag or bladder in combination with the fluiddischarge port of an accumulator to restrain the portion of the bagadjacent to the fluid 'port and prevent abnormal stress in the bag overthe entire area between the central axis and the retained circumferenceof the bag.

A still further object of this invention is to provide an accumulatorwith a bag or bladder mounted therein in which the fluid discharge portof the accumulator provides a supporting means to affix the zone of thebag or bladder adjacent thereto in a resilient manner to prevent anyabnormal stresses on the bag or bladder over the entire area between thecentral axis and the retained circumference of the bag or bladder.

Other objects of this invention will be apparent by reference to theaccompanying detailed description and drawings in which Fig. 1illustrates an accumulator with a deformable bag according to thisinvention, and

Fig. 2 illustrates a similar accumulator illustrating a furtherembodiment of this invention.

Referring to Fig. 1 there is illustrated an accumulator shell ill havingtwo apertures H and i2 at opposite ends thereof in which a deformablebag I4 is mounted, the deformable bag having an air port 55 at one endthereof and a container It mounted within the bag at the opposite endthereof. The container it is formed either integral with the bag oraflixed thereto in any manner to retain the container in the positionillustrated in the drawing. The end of the bag Hi at which the containerii; is affixed is provided with an aperture 9. The bag is mounted withinthe accumulator by passing same through the aperture l2 of the shell iiiand passing the air valve l5 through the aperture i E and threadablysecuring and locking the air valve in place as indicated in the drawing.A resilient spring 8 is mounted within the container 16 and a piston rod1 is mounted through the aperture 8 of the bag It, the piston rod 1having a piston head 6 upon which the resilient spring 8 may be seated.A bushing 5 surrounding the rod '1 is affixed or sealed in the aperture9. An oil port plug i8 is mounted in aperture l2 and the plug 58 isprovided with a piston rod supporting disc 4 so that the piston rod 1may be secured in any manner, such as threading into disc 5, asillustrated in the drawing. The disc 4 is provided with a plurality ofbores 3; the bores 3 permit the fluid ingress and egress through the oilport plug. The oil port plug 18 when mounted in aperture i2 is providedwith a split ring 19 which is compresse and passed through the aperturei2 and then spread into the position illustrated in the drawing to lockthe plug l8 within the accumulator shell as illustrated. A seal 2% ispositioned in the aperture 12 and a lock ring 2| is secured about theplug 18 to force the seal 20 into a tight relationship with the aperturel2 and the periphcry of the plug H3. The ring 2| may be locked in placeby a lock nut 22 and the plug I8 may be provided with the usual fluidport 23.

It will be noted that the normal expansion and contraction of the bag l4during the egress and ingress of fluid through the oil port plug l8 willcause a sliding engagement of the bushing 5 on the rod 1. At the sametime the bag it expands, the spring 8 mounted within the container I6will be compressed, or as the bag it contracts, the spring 8 willexpand. Thus with a spring 8 of pre-determined characteristics the forceof spring 8 when compressed can be pre-determined to be sufficient toprevent the normal expansion of the bag It to its full degree touchingand closing the fluid discharge port; thus the restraining eifect ofspring 8 is transmitted through the container 16 and its walls to thearea of the bag or bladder adjacent to the fluid discharge port. It isalso to be noted that with the bag or bladder l4 attached to the centralaxis of the accumulator, at one end by the air port plug it and by meansof bushing 5 to the rod 7 on the central axis of the accumulator, thebag it is thus attached at both ends to the central axis of theaccumulator, being aflixed at one end and slideably attached at theopposite end. Thus the normal expansion and contraction of the bag isretained in a concentric fashion. It is also to be noted that with thebag It formed slightly conical at the fluid discharge end that thenormal expansion of the bag 14 is so designed that the bag walls willexpand to a restrained position against the inner periphery of the shell5% and normally remain restrained at that position allowing theremainder of the bag wall not in con tact with the shell wall to furtherexpand until the complete bag wall is in contact with the innerperiphery of the shell. During this expansion it is preferable toprevent any rubbing or abrasive movement between the exterior bag walland the interior periphery of the shell; to insure this perfectexpansion it is necessary to retain the bag end in this case theaperture 9 on the central axis of the accumulator. In this invention asillustrated the abnormal stresses that are created in the area of thebag nearest to the fluid discharge port are eliminated or at leastgreatly decreased due to the restraining effect of the container l5 andthe resilient spring 8. Thus the bag id in this instance should performin a normal manner to produce an unlimited length of operation withoutrupture and permit the most efficient use of the accumulator.

A further embodiment of this invention is illustrated in Fig. 2 in whichsimilar structure is illustrated except that the spring 55A is a springmounted to operate in tension rather than in compression; to insure thisfunction of operation, the rod 1A is extended up into the container I6and the spring 8A is affixed to the end of the rod 1A, the spring 8Abeing mounted about the,

rod 7A and at its opposite end it is afiixed to or embedded in the bagor bladder i i, otherwise, the construction of the accumulator remainsthe same as that illustrated in Fig. 1. In operation the bag or bladderI4 will expand or contract according to the egress or ingress of fluidthrough the fluid port [8 and during the expansion and contraction ofbag It, spring EA will restrain the normal expansion of bag l4 andprevent bag M.

from touching and closing the fluid port 23. During the contraction ofbag It, spring 8A will assist the bag in returning to a contractedposition.

It is apparent that various changes and modifications may be made suchas mounting any type of resilient means within the container it toperform similar to the resilient means illustrated without departingfrom the spirit of this invention and this invention shall be limitedonly by the appended claims.

What is claimed is:

1. In an accumulator comprising a shell having two ports, a deformablebag secured within said shell separating said two ports from each other,the deformable bag having an air valve which is mounted in the one port,the opposite end of said deformable bag having a sealed containermounted within said bag and an aperture connecting said container withthe exterior of said bag, a fluid outlet plug mounted in the oppositeport of the said shell, a piston rod affixed at the central axis of thefluid outlet plug and extending into said accumulator, said piston rodfitted through the aperture in said deformable bag, a piston headaflixed to the end of said piston rod within said container, acompression spring mounted in said container between the piston head andthe opposite end of said container, means to expand said deformable bagwithin said shell, and means to restrain the area of said deformable bagadjacent to the fluid outlet plug from expanding to contact said fluidoutlet port.

2. In an accumulator comprising a shell having two ports, a deformablebag secured within said shell separating said two ports from each other,the deformable bag having an air valve which is mounted in the one port,the opposite end of said deformable bag having a sealed containermounted within said bag and an aperture connecting said container withthe exterior of said bag, a fluid outlet plug mounted in the oppositeport of the said shell, a piston rod affixed at the central axis of thefluid outlet plug and a bushing mounted on said rod to reciprocate onsame, said bushing being bonded to the aperture in said accumulator bag,said piston rod extending through said bushing into said container, apiston 6 l head aflixed to the end of said piston rod within saidcontainer, a compression spring mounted in said container between thepiston head and the opposite end of said container, means to expand saiddeformable bag Within said shell, and means to restrain the area of saiddeformable bag adjacent to the fluid outlet plug from expanding tocontact said fluid outlet port.

3. In a device according to claim 2 in which said container is formed ofa non-resilient material and in which said container is affixed at itsbase to the interior surface of the bag at the zone that is adjacent tothe fluid outlet plug.

4. In an accumulator comprising a shell having two ports, a deformablebag secured within said shell separating said two ports from each other,the deformable bag having an air valve which is mounted in the one port,the opposite end of said deformable bag having a sealed containermounted within said bag and an aperture connecting said container withthe exterior of said bag, a fluid outlet plug mounted in the oppositeport of the said shell, a piston rod affixed at the central axis of thefluid outlet plug and extending within said shell and into the containerwithin said bag, said piston rod fitted through the aperture in saiddeformable bag, a tension spring mounted about said rod and afiixed atone end to said rod and at its opposite end affixed to the' bag, meansto expand said deformable bag within said shell, and means to restrainthe area of said deformable bag adjacent to the fluid outlet plug fromexpanding to contact said fluid outlet port.

JEAN GEORGES MERCIER. EDWARD M. GREER.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 2,342,355 Mercier Feb. 22, 19442,342,356 Mercier Feb. 22, 1944

